_hw_usb_stat Union Reference

HW_USB_STAT - Status register (RO) More...

#include <MK64F12_usb.h>

Detailed Description

HW_USB_STAT - Status register (RO)

Reset value: 0x00U

Reports the transaction status within the USB module. When the processor's interrupt controller has received a TOKDNE, interrupt the Status Register must be read to determine the status of the previous endpoint communication. The data in the status register is valid when TOKDNE interrupt is asserted. The Status register is actually a read window into a status FIFO maintained by the USB module. When the USB module uses a BD, it updates the Status register. If another USB transaction is performed before the TOKDNE interrupt is serviced, the USB module stores the status of the next transaction in the STAT FIFO. Thus STAT is actually a four byte FIFO that allows the processor core to process one transaction while the SIE is processing the next transaction. Clearing the TOKDNE bit in the ISTAT register causes the SIE to update STAT with the contents of the next STAT value. If the data in the STAT holding register is valid, the SIE immediately reasserts to TOKDNE interrupt.

Definition at line 1919 of file MK64F12_usb.h.